Adapter for Connecting an Auxiliary Handle to a Hand-Held Power Tool

ABSTRACT

The present invention relates to an adapter for connecting an auxiliary handle to a hand-held power tool and which includes an adapter body, which is connectable to the hand-held power tool, and an adjusting guide, which is attached to the adapter body such that it is movable relative thereto, and wherein the auxiliary handle is connectable to the adapter body by means of the adjusting guide and the adjusting guide is capable of fixing the auxiliary handle on the adapter body in different positions relative to this same structure.

The invention relates to an adapter for connecting an auxiliary handle to a hand-held power tool.

A hand-held power tool of this kind can comprise a driven hand-held power tool having a housing and a drive accommodated within the housing, wherein a tool holder and, where appropriate, a tool accommodated therein can be driven with the said drive. The housing can serve as a handle for the hand-held power tool, in that it has at least one elongated portion for grasping.

Typically, a hand-held power tool of this kind can comprise an angle grinder. In angle grinders, it is standardly provided that these have an auxiliary handle, for better and secure handling, when the inserted tool is a grinding disc having a diameter of more than 100 mm. With the aid of the auxiliary handle, the user can grip the hand-held power tool with both hands and, in this way, support it against counter-torques which are generated during the machining.

Accordingly, on a large number of known angle grinders, two or three locating positions at which the auxiliary handle can be screwed to the gearbox are predefined. If the angle grinder is intended for use in cramped spatial conditions, however, these locating positions of the auxiliary handle cannot always though be utilized for the machining, since this auxiliary handle would protrude too far over the angle grinder.

From the prior art, as disclosed by document DE 198 54 468 A1, is known a hand-held power tool in which, for a variable arrangement of an auxiliary handle on the hand-held power tool, a guide groove is provided as an adjusting guide on the outer periphery of the housing of the hand-held power tool, in which guide groove a guide body of the auxiliary handle is guided and can be positively fixed in a plurality of angular positions relative to the housing.

In this solution, it can be regarded as a drawback, however, that a retrofitting of an adjustable auxiliary handle of this type onto known hand-held power tools of the type described in the introduction is not possible. Furthermore, the mechanism for fixing the auxiliary handle to the adjusting guide is of comparatively complicated construction and is thus associated with additional time and cost expenditure both in manufacture and assembly.

In addition, DE 10 2004 016 088 A1 discloses an auxiliary handle arrangement in which a bearing element which is pivotable in relation to the housing of an angular grinding tool can be fixed in various positions. The bearing element supports the side handle and is pivotable in relation to the housing via two bearing points. Moreover, the side handle is displaceable along a groove in the bearing element, relative to this same, in different positions.

In this solution, it can be a drawback that, in an adjustment of the side handle, three fastening points may have to be loosened and refixed, namely the two bearing points and the fastening screw of the side handle. This is time-consuming for the user, so that he will often dispense with the setting of an optimal position of the side handle in favour of time saving.

Finally, DE 10 2007 012 300 A1 also discloses a handle which, via a screw-shaped fastening element, can be fastened fixedly to a machine housing. Adjustability of the angular position of the handle relative to the housing is not provided.

In contrast, one object of the present invention consists in providing an arrangement for connecting an auxiliary handle to a hand-held power tool, which arrangement at least partially eliminates the above-stated drawbacks.

According to the invention, this object is achieved by virtue of the fact that an adapter for connecting an auxiliary handle to a hand-held power tool is provided, which adapter has an adapter body, as well as an adjusting guide which is attached to the adapter body such that it is movable relative thereto. The adapter body is connected or connectable to the hand-held power tool. In addition, according to the invention, the auxiliary handle is connectable to the adapter body by means of the adjusting guide and the adjusting guide is disposed between the adapter body and the auxiliary handle and is capable of fixing the auxiliary handle on the adapter body in different positions relative to this same. The auxiliary handle is adjustable with the aid of the adapter in at least two mutually different motional directions relative to the hand-held power tool, wherein the adapter body, at least in sections, has on its outer peripheral surface a profiling comprising a polygonal profile with substantially plane or concave profile surfaces.

In this context, it should be pointed out that embodiments of the kind in which, in addition to the adjusting guide, still further elements are disposed between the adapter body and the auxiliary handle are also intended to be covered hereby.

By two mutually different motional directions are meant motional directions of the kind which (irrespective of whether they run linearly or in a curve and whether they are equidirectional or oppositely directed) do not run parallel to each other. Possible motional directions can be a first pivotal direction about a first axis and a second pivotal direction about a second axis, wherein the axes do not lie parallel, but transversely to each other. A combination of a linear motion in a first motional direction and a pivotal motion in a second motional direction is also conceivable.

In the present invention, the adjusting guide serves to connect the auxiliary handle to the adapter body and consequently to a hand-held power tool which is connectable thereto, wherein an adjustment of the auxiliary handle relative to the hand-held power tool in different positions is possible.

Through the provision of a profiling on the adapter body, a non-positive connection is provided. This profiling can be configured, in particular, such that the end portion of the auxiliary handle is in sections capable of engaging in the profiling or is capable of at least resting against the said profiling, where appropriate with a corresponding counter-profiling, in order to positively connect the adjusting guide to the adapter body. In this conceivable embodiment, the adjusting guide has a recess in which a portion of the adapter body is accommodated, so that the adjusting guide can be displaced along the adapter body and pivoted around this.

Alternatively to this design variant, an embodiment in which the adjusting guide is guided at least partially within a recess of the adapter body (like a guide groove) is also, however, conceivable. This recess can run, for instance, along the adapter body. In such an embodiment, additional recesses on the adapter body which open out into in the guide groove can serve to pivot the adjusting sleeve relative to the adapter body. In addition, the guide groove can have on its inner side an additional profiling and, the adjusting sleeve furthermore, on its outer periphery accommodated therein, can optionally have a corresponding counter-profiling.

According to the invention, the profiling of the adapter body comprises a polygonal profile, which has substantially plane or concave profile surfaces.

For instance, the adapter body can in sections comprise a hexagonal profile (with a cross section in the shape of an equilateral hexagon). Correspondingly, the end portion of the auxiliary handle or the clamping element can have a plane end face, which is capable of bearing against a side edge of the polygonal profile of the adapter body. Alternatively, the end face can also of course have, instead of a plane face, a counter-contour to the polygonal profile. In the case of concave, i.e. viewed in cross section inwardly curved profile surfaces as side faces of the polygonal profile, the end face can analogously have a counter-contour corresponding hereto.

In a refinement of the present invention, the adapter body is here configured such that it is connectable to the hand-held power tool and is pivotable relative to the latter about a first axis.

The adapter thus comprises two constituent parts which are movable relative to the hand-held power tool, namely the pivotably arranged adapter body and the adjusting guide movable relative to the adapter body (and thus also to the hand-held power tool). In this way, the auxiliary handle can be easily positioned relative to the hand-held power tool and thus adapted to the spatial conditions which exist during the machining.

In addition, the adapter body, for instance, can be detachably connectable on the hand-held power tool, so that it, and thus also the whole of the adapter, are detached when the hand-held power tool is not in use.

Furthermore, the adapter can comprise at least one fastening means, which is insertable into at least one receiving opening of the hand-held power tool. Such a fastening means can be used to fasten the adapter body of the adapter to the hand-held power tool, so that hand-held power tools known from the prior art can also be retrofitted with the adapter. In particular, the fastening means can comprise an external thread, which can cooperate with a corresponding internal thread of the receiving opening of the hand-held power tool for the detachable fastening of the adapter to the hand-held power tool. In this way, the adapter, if need be, can be screwed to the hand-held power tool, or removed therefrom when not required.

In addition, the adapter body can preferably be of arc-shaped configuration, wherein it can be fastened in the region of its end portions, via two fastening means, to the hand-held power tool. The fastening means here act as fastening points, which jointly form the first axis about which the adapter body can be pivoted.

Alternative designs, for instance an embodiment in which the adapter body is attached at just one fastening point to the housing of the power tool, the fastening point simultaneously serving as a pivot bearing, are likewise, of course, conceivable.

It can further be provided that the adjusting guide, at least in sections, is displaceable along the adapter body and/or is pivotable about the adapter body. Different alternative embodiments and combinations hereof are here conceivable, for instance wherein the adapter body has at least one portion on which the adjusting guide is displaceable relative to the adapter body, and a further portion about which the adjusting guide is pivotable. The two portions can coincide, partially overlap, be arranged adjacent to each other or at a distance apart.

In addition, it can be provided that the adjusting guide has at least one recess, in which an end portion of the auxiliary handle is capable of engaging and/or through which the end portion of the auxiliary handle is capable of extending in order to secure the adjusting guide in its position on the adapter body.

The recess on the adjusting guide can thus, on the one hand, assume the function of connecting the adapter to the auxiliary handle and, on the other hand (alternatively or additionally), the function of enabling the adjusting guide to be secured to the adapter body with the aid of the end portion of the auxiliary handle. In addition, the adjusting guide can also however have a plurality of recesses, of which a first recess serves to receive an end portion of the auxiliary handle, whilst a second recess can be extended through by an additional clamping element, which serves to secure the adjusting guide in its position on the adapter body.

Furthermore, the at least one recess of the adjusting guide can comprise an internal thread, and the end portion of the auxiliary handle can have a corresponding external thread with which the auxiliary handle can be screwed into the recess of the adjusting guide. Should a second recess be provided to receive a separate clamping element, this can likewise comprise an internal thread, in which a corresponding external thread of the clamping element engages.

With the aid of an end portion of the auxiliary handle, or alternatively with the aid of a corresponding separate clamping element, which end portion or separate clamping element extends through the recess provided on the adjusting guide in order to clamp the adjusting guide to the adapter body, a non-positive connection, which already enables a good and reliable securement of the adjusting guide to the adapter body, is achieved.

The adapter body, as also the adjusting guide, can be made at least partially of a metallic or metal-containing material in order to enable the stablest possible supporting of the auxiliary handle. The adjusting guide and/or the adapter body can also however alternatively be formed, at least partially, of a plastic. The latter is particularly advantageous, since a weight saving can hereby be achieved. For example, the internal thread which is optionally configured on a recess of the adjusting guide can be incorporated directly into the adjusting guide. Alternatively, an additional threaded sleeve (which is made, for instance, of a different material from the adjusting guide) can also however be inserted in the recess of the adjusting guide. This latter is particularly advantageous if the adjusting guide is made of a plastic.

Finally, the present invention relates to a hand-held power tool having an auxiliary handle and an adapter which has the above-stated features, wherein the auxiliary handle is connectable via the adapter to the hand-held power tool and is fixable in different positions relative to the hand-held power tool.

The invention is described in greater detail below with reference to the appended figures.

The appended figures show, by way of example, a preferred embodiment in which the individual features of the invention are mutually combined. However, the person skilled in the art will also, of course, be able to view these also in isolation and/or to combine these into other sensible combinations.

In schematic representation:

FIG. 1 shows an isometric view of an inventive hand-held power tool having an adapter for the connection of an auxiliary handle; and

FIG. 2 shows the inventive hand-held power tool according to FIG. 1 in a partially sectioned view.

FIG. 1 shows an isometric view of an inventive hand-held power tool, which is denoted in general terms by the reference symbol 10.

The represented hand-held power tool is constituted by an angle grinder of known type. This can be powered, as in the represented embodiment (indicated by the power line I) via alternating current, or with the aid of a connectable battery pack.

The hand-held power tool 10 comprises a housing 12, in which a drive, for instance an electrical drive motor (not represented) as in the present embodiment, can be accommodated. As can clearly be seen in FIGS. 1 and 2, the housing 12 is adjoined by a gearbox 14, in which a corresponding angular gear (not represented) for diverting and transmitting the drive motion to a tool holder 16 is accommodated.

To the tool holder 16 can be attached, for instance, a grinding disc as the tool. The hand-held power tool 10 further has a protective hood 18.

Also attached to the hand-held power tool 10 is an auxiliary handle 20, which in the shown example is damped, and which has a grip part 22, a damping part 24 and a mounting flange 26. The damping part 24 is made of an elastomer and damps the transmission of vibrations from the hand-held power tool 10 to the grip part 22. Alternatively, the handle 20 can also, of course, be of non-damped configuration and can comprise, for instance, just a grip part 22 and a fastening part 28.

In the present representation, the fastening part 28 penetrates both the mounting flange 26 and the damping part 24 and grip part 22. As is more clearly apparent in FIG. 2, the fastening part 28 has a plurality of projections which extend radially to the longitudinal axis L and which, by virtue of being back-gripped by the damping part 24 and the mounting flange 26, provide an axial locking of the arrangement. In addition, a radial locking can be achieved by corresponding, peripherally arranged projections 22 a on the grip part 22 and, where appropriate, additionally on the damping part 24 and/or the mounting flange 26 (these are not however represented), i.e. a radial relative motion between the fastening part 28 and the remaining part of the auxiliary handle 20 can at least be reduced. A rotary motion of the grip part 22 about the longitudinal axis L can thus be transmitted to the fastening part 28.

The fastening part 28 of the auxiliary handle 20 has an end piece (end portion) 28 a which is facing away from the grip part 22 and which serves to fasten the auxiliary handle 20 to the inventive adapter 30.

In the represented embodiment, the inventive adapter 30 comprises a bow-shaped or arc-shaped adapter body 32, the end portions of which can be fastened via fastening means 34 to the gearbox 14 of the hand-held power tool 10. For this can be used, for instance, screw-shaped fastening means 34 a, which can be screwed into recesses 14 a anyway provided on the gearbox and having a corresponding internal thread.

The fastening points which are formed by the fastening screws 34 a jointly form a rotational axis D, about which the adapter body 32 can be pivoted once the fastening screws 34 a are slightly loosened and do not clamp the said adapter body against the gearbox 14. The orientation of the adapter body 32 relative to the gearbox 14 and the rest of the hand-held power tool 10 can thus be altered by gentle loosening of the two fastening screws 34 a.

In addition, the adapter 30 comprises an adjusting guide 36, to which the auxiliary handle 20 is fastened by its end portion 28 a. As can better be seen in FIG. 2, the adjusting guide 36 has a through bore 36 a, through which the arc-shaped portion of the adapter body 32 can extend. In the represented embodiment, the through bore 36 a is here configured such that it at least partially corresponds with its inner contour to the outer contour of the received adapter body portion. In FIG. 2, it can clearly be seen that the adapter body, at least in sections, has a uniform hexagonal profile.

As in the shown example, the inner recess 36 a can have one or more side faces (in FIG. 2 three), which form a counter-contour to this hexagonal profile in order to enable a defined bearing contact of the adjusting guide 36 in a state placed against the adapter body 36 and secured. Both the outer peripheral surface of the adapter body and the inner peripheral surface of the inner recess can have, however, an alternative design.

In addition, the adjusting guide 36 also comprises a recess 38, which in the represented embodiment extends radially to the through bore 36 a and serves to receive the end portion 28 a of the auxiliary handle 20. For this purpose, the latter is screwed by its external thread into a corresponding internal thread of the recess 38. The recess 38 opens out radially into the through bore 36 a, so that the end portion of the auxiliary handle 20 can be brought into direct contact with the adapter body 32 when this is screwed just far enough down into the recess 38.

In this way, the end portion 28 a of the auxiliary handle 20 serves not only to fasten the auxiliary handle 20 to the adapter 30, but also to fix the auxiliary handle 20 relative to the adapter 30. Thus the through bore 36 a on the adjusting guide 36 is dimensioned sufficiently large that the adjusting guide 36, without the auxiliary handle 20, can be moved freely relative to the adapter body 32. This comprises both a motion along the adapter body and a pivot motion around this same. If the auxiliary handle 20 is now attached to the adjusting guide 36 and screwed into the recess 38 to the point where its end portion 28 a comes to bear against the adapter body 32, then the adapter body 32 is pressed with its outer peripheral surface against the inner peripheral surface of the through bore 36 a. A clamping which is sufficient for secure fixing of the auxiliary handle 20 is hereby achieved, since any further adjusting motion of the adjusting guide 36 relative to the adapter body 32 is prohibited.

If the user thus wishes to adjust an auxiliary handle 20, connected via the adapter 30 to the hand-held power tool 10, relative to the hand-held power tool 10, then he has several options: on the one hand, he can pivot the adapter body 32 itself relative to the hand-held power tool 10 about the rotational axis D in order, where appropriate, to lessen the distance between the gearbox 14 and the arc-shaped portion of the adapter body 32 and to compress the front portion of the hand-held power tool 10 with tool holder in terms of its external dimensions. In addition, via a twisting motion of the grip part 22 of the auxiliary handle 20 about the longitudinal axis L, he can detach the auxiliary handle by its end portion 28 a partially from the recess 38 on the adjusting guide 36, or can screw it deeper into this same. Depending on whether he somewhat releases or fixingly screws in the auxiliary handle 20, the adjusting guide can be moved relative to the adapter body 32 or is fixed relative to this same. Consequently, the user does not even have to release his hand from the auxiliary handle in order, where appropriate, to readapt the concrete orientation of the auxiliary handle 20 to his current requirements. A very flexible auxiliary handle, which can be fixed in a large number of different positions relative to the hand-held power tool, is thus obtained. 

What I claim is:
 1. An adapter for connecting an auxiliary handle to a hand-held power tool, comprising: an adapter body, which is connectable to the hand-held power tool; and an adjusting guide, which is attached to the adapter body such that it is movable relative thereto, and wherein the auxiliary handle is connectable to the adapter body by means of the adjusting guide, and wherein the adjusting guide is disposed between the adapter body and the auxiliary handle and is further capable of fixing the auxiliary handle on the adapter body in different positions relative to the adapter body, and wherein the auxiliary handle is adjustable with the aid of the adapter body in at least two different motional directions relative to the hand-held power tool, and wherein the adapter body, at least in sections, has on its outer peripheral surface a profiling comprising a polygonal profile with substantially planar or concave profile surfaces.
 2. An adapter according to claim 1, and wherein the adapter body is connectable to the hand-held power tool and is pivotable relative to the hand-held power tool about a first axis.
 3. An adapter as claimed in claim 2, and wherein the adapter further comprises at least one fastening means, which is insertable into at least one receiving opening of the hand-held power tool.
 4. An adapter as claimed in claim 3, and wherein the adjusting guide, at least in sections, is displaceable along the adapter body and/or pivotable about the adapter body.
 5. An adapter as claimed in claim 4, and wherein the adjusting guide has at least one recess, in which an end portion of the auxiliary handle is capable of engaging and/or through which the end portion of the auxiliary handle is capable of extending in order to secure the adjusting guide in its position relative to the adapter body.
 6. An adapter as claimed in claim 5, and wherein the at least one recess of the adjusting guide comprises an internal thread, and the end portion of the auxiliary handle has a corresponding external thread with which the auxiliary handle can be screwed into the recess of the adjusting guide.
 7. An adapter as claimed in claim 6, and wherein the adapter body and the adjusting guide are made at least partially of a metallic or metal-containing material.
 8. A hand-held power tool having an auxiliary handle comprising: an adapter and wherein the auxiliary handle is connectable via the adapter to the hand-held power tool and is fixable in numerous positions relative to the hand-held power tool. 